Brain Neoplasms3073 (1)

7/27/2019 Brain Neoplasms3073 (1)

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Brain Neoplasms:

General Considerations

1. Comprise: 10% of all tumors

2. Most common childhood neoplasms

3. Peak incidence at 5th decade

4. Supratentorial tumors in adults

5. Infratentorial tumors in childhood



Brain Neoplasms:

General Considerations

6. Different tumors in different ages

7. Primary tumors infiltrative, metastatic

well-demarcated

8. Intraneural seeding occur, but noextraneural metastasis

9. Produce neurologic symptoms by size,location, invasiveness, and secondaryeffects



Var ieties of brain tumors

Meninges: meningioma, hemangiopericytoma

Astrocytes: astrocytoma (various types)

Oligodendrocytes: oligodendroglioma

Ventricles: ependymoma, choroid plexus papilloma,

colloid cyst

Vascular: hemangioblastoma

Primitive cells: germinoma, medulloblastoma,

neuroblastoma, pineoblastoma, retinoblastoma

Neuronal: ganglioglioma, gangliocytoma Pituitary: adenoma, craniopharyngioma

Nerves: schwannoma, neuroblastoma



I ncidence of I ntracranial Gl iomas (All ages)

Glioblastomas

Astrocytomas

Ependymomas

Medulloblastomas

Oligodendrogliomas

Choroid plexus papillomas

Colloid cysts

55.0%

20.5%

6.0%

6.0%

5.0%

2.0%

2.0%



I ncidence of Primary Intraspinal I ntramedul lary Gliomas

Ependymomas

Astrocytomas (grades 1 and 2)

Glioblastomas(Astrocytomas grades 3 and 4)

Oligodendrogliomas

Other tumors

63.0%

24.5%

7.5%

3.0%

2.0%



Frequent brain tumors

Meningioma

Astrocytoma/glioblastoma

Oligodendroglioma

Ependymoma Medulloblastoma

Schwannoma/neurofibroma

Phakomatosis



Meningioma

Arachnoid cells origin Attached to dura, subduralCommon sites

Changes in craniumHyperostosisInvasion

Microscopic: whorls and psammoma bodies











Gliomas

Astrocytes- astrocytomas

– Fibrillary

– Pilocytic

Oligodendrocytes- oligodendrogliomas Ependyma- ependymomas



Astrocytomas

Adul ts :

Chi ldhood:

SupratentorialSolidMalignant

InfratentorialCysticBenign



Adult vs chi ldhood astrocytomas

Adult: fibrillary. Grading varies from low grade

malignancy to one of most malignant brain

tumor.

Childhood: pilocytic. Very low grade tumor

(benign).



F ibr i l lary astrocytomas

Grossly solid

Common in cerebral hemispheres

Low grade in young, higher grade in older

Grading – astrocytoma (low grade)

– Anaplastic astocytoma

– glioblastoma multiforme





F ibr i l lary astrocytoma: microscopic

Low grade- hypercellularity, pleomorphism

Anaplastic- as above plus mitosis, vascular

endothelial proliferation

Glioblastoma multiforme- as above plusnecrosis and pseudopalisades. Grossly

variegated appearance (multiforme)









Pilocytic astrocytoma

Common in childhood

Most slow growing of the gliomas

Sites: cerebellum, around III V., optic nerve

Grossly cystic with mural nodule Microscopic

– elongated hair-like (pilo) elongated cells

– Rosenthal fibers



Rosenthal f iber def ini tion

Dense, eosinophilic fibers within cytoplasmic

processes of astrocytes.

Correspond to aggregate accumulation of

intermediate filaments in these processes.







Oligodendroglioma

Slow growing tumor

Potentially malignant

Calcifications







Tumors in Ventr icles

1. Ependyma: Ependymoma

2. Choroid Plexus: Papilloma



Ependymomas

Arise from ependymal lining- ventricles and

central canal of spinal cord

Common in childhood

4th V. common in cerebrum

Most common tumor of spinal cordparenchyma in adult

Microscopic

– perivascular pseudorosettes

–ependymal rosettes







Primitive neuroectodermal tumors

Neuroblastoma- cerebral hemispheres

Medulloblastoma- cerebellum

Ependymoblastoma- ventricles

Pineoblastoma- pineal region



Medulloblastoma

Origin: primitive neuroectodermal cells Age: 1st decade of life

Site: vermis of cerebellum

May cause hydrocephalus

Subarachnoid dissemination





H istologic patterns: def ini tions



H istologic patterns: def ini tions

Whorls: onion-skinning pattern of tumor cells

Psammoma bodies: laminated calcium

Pseudopalisading: lining up of the tumor cells

around a central necrotic area

Palisade: lining up of tumor cells around their

own cytoplasmic processes. No necrosis.

Pseudorosette: tumor cells around blood

vessels, cells equidistant from vessel walls.

Rosettes: tumor cells around central lumen or fibrillary area of cellular processes



T f N R t



Tumors of Nerve Roots

and Per ipheral Nerves

1. Schwannomaviii Cranial nerve (Acoustic sch.)Spinal roots, posterior

Peripheral nerves

2. NeurofibromaSpinal Roots, rarePeripheral nerves

3. Malignant variantsRare



Peripheral nerve tumors

Schwannoma

Schwann cells

Compress the nerve trunk

Encapsulated

Easily resectable withoutnerve damage

Microscopic:

– Antony A and B fibers

– Verocay bodies

Neurofibroma

Schwann cells, neurites,

fibroblasts

Fusiform and involves

nerve trunk Not encapsulated

Not resectable without

sacrificing nerve

Micro- Intermingled cellswith wavy nuclei





Metastatic brain tumors



Metastatic brain tumors

Most common brain tumor in adults.

Common primary sites: melanoma, lung,breast, GI tract, kidney.

Most are in cerebrum (MCA territory).

In gray-white junctions due to rich capillarity

Discrete, globoid, sharply demarcated

tumors. Amenable to surgical resection.

Single or multiple.

Brain edema frequent.





Phakomatosis: def inition

Phakos (Greek): lentil mole or freckle.

Neurologic abnormalities combined with

defects of skin or retina, explained by their

common ectodermal origin.

Involvement of visceral organs

Phakomatosis



Phakomatosis

(Neurocutaneous dysplasia)

1. Neurofibromatosis (von Recklinghausen's dis.)

2. Tuberous Sclerosis

3. Sturge-Weber disease (Encephalofacial Angiomatosis)

4. von Hippel-Lindau Disease

5. Neurocutaneous Melanosis

Neurofibromatosis



1. Dominant inheritance

2. Multiple neurofibromasCentral - CNSperipheral nerves

3. Increased incidence of:meningiomagliomaschwannoma - bilateral VIII N.

4. Cafe-au-lait (melanosis) in skin5. Elephantiasis: increased connective tissue



Tuberous Sclerosis



Tuberous Sclerosis

1. Dominant inheritance

2. Clinical triad:seizuresmental retardationadenoma sebaceum

3. Retinal hamartoma (phakoma)

4. Tubers in cerebral cortex

5. Subependymal giant cell astrocytoma

6. Hamartomas in other organs: heart, kidney





Venice



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Brain Neoplasms3073 (1)